[labnetwork] troubleshooting an e-beam source

[Nathanael Sieb]

Hi all,

We are trying to trouble-shoot a PVD e-beam source and can't seem to 
figure out the problem.  Early in the year we sent the assembly out for 
repair and refurbishment. (we burned a hole in the internal bellows 
tubing, long story)  When we got it back we connected it back to the 
system and started it up.  However, we haven't been able to get a stable 
emission current.  The HV stays on but the filament current, and hence 
emission current, occasionally cuts out.  It comes back a second later, 
over-shoots the target current, and then restabilizes.  It happens at 
low emission currents and some higher ones.  The timing is random. 
Sometimes it happens frequently, sometimes you can run 15 min without a 
problem.  There are no errors from the power supply.

We took a video of the issue and it happens at around the 1min mark here 
<https://www.dropbox.com/s/7n42e38qviju7ga/Both_emission_and_filament_spiking_and_turning_off.mov?dl=0>. 
The advice from vendors was to look for a loose connection.  We have 
checked all the external connections and tried to look at the internal 
ones too.  Last week we removed the filament and reinstalled it.  We 
didn't see any problems and we still have the same issue.

We're running out of ideas other than sending it back to the vendor to 
examine the entire assembly again.  Has anyone else encountered this 
type of problem?  Any suggestions?

Thanks,
Nathanael

*Nathanael Sieb *
Director of Operations and Administration  | 4D LABS 
<http://www.4dlabs.ca/>
Simon Fraser University
8888 University Dr., Burnaby, B.C. V5A 1S6
T: 778.782.8084 | F: 778.782.3765 | www.4dlabs.ca <http://www.4dlabs.ca>
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